1. Field of the Disclosure
The present application relates to a method of manufacturing an organic light emitting display device, and more particularly to a manufacturing method of an organic light emitting display device adapted to realize high definition and a larger size.
2. Description of the Related Art
The organic light emitting display devices are self-illuminating display devices. As such, the organic light emitting display devices do not need any separated light source which is used in a liquid crystal display device. In accordance therewith, the organic light emitting display devices can become lighter and thinner. Also, the organic light emitting display devices have the features of wider viewing angle, superior contrast, and lower power consumption than those of the liquid crystal display devices. Moreover, the organic light emitting display devices can be driven by a low direct-current voltage and provide a high speed response. Furthermore, the organic light emitting display devices can well resist external impacts and be used in a wide temperature range because of having solid components.
Such an organic light emitting display device includes two electrodes stacked on a substrate, and a light emission layer EML interposed between the two electrodes. The light emission layer EML is patterned using one of a fine metal mask method, an ink-jet method, a lift-off method and so on.
The fine metal mask method cannot be applied to a large-sized and high definition display device due to technical limitations of mask formation. More specifically, a large-sized mask droops due to its weight and forces a desired pattern to be not formed. Also, the spread of an organic material is aggravated due to a separate distance between its deposition portion and the mask. As such, it is difficult to realize high definition.
The ink-jet method jets a liquid material. As such, organic light emitting elements must be exposed while the process is being performed. Due to this, the performance of the organic light emitting element must deteriorate.
Other methods using the existing etch process enable a metal to be in direct contact with an etchant. Due to this, a disconnection fault can be generated. Also, it is difficult to control etch-depth. As such, properties of the organic light emitting element can deteriorate.
The lift-off method can form a fine pattern using only an exposure process and a development process without an etch process, unlike a photo mask procedure including the exposure, development and etch processes. When a photoresist pattern is removed, a residual film is caused by strong adhesion force of the photoresist and an organic light emission layer EML must be exposed to a solvent which is used to remove the photoresist pattern. As such, a fault of the organic light emission layer EML can be caused by the residual film and the solvent. Due to this, luminous properties of the organic light display device must deteriorate.